Brown thighs in oil in the skillet, then remove and set aside for a bit.
Add onions, ginger, garlic, and chopped peppers to pan and cook until onions brown lightly.
Stir in the coconut milk, diced tomatoes, chicken broth, saffron water, brown sugar, lime juice, coriander and curry powders.
Bring mixture to a boil, then reduce heat, cover and simmer for thirty minutes.
At that time, use the stick blender to puree the sauce. You could also use a blender but make sure the sauce cools down a bit before using that appliance.
Once sauce is pureed, add chicken back to pan, cover and simmer thirty minutes more.